Pneumatic pipe plug

Abstract

A pneumatic pipe plug for pipeline tee-connections and access ports having a molded cap structure, an elastomeric inflatable body, and a sealant ring. The molded cap structure of the pneumatic pipe plug having two concentrically spaced projections which act to receive and seal the elastomeric inflatable body. The elastomeric inflatable body having a closed bottom and an open top which has a peripheral shoulder extending therefrom. The sealant ring of the pneumatic pipe plug having a threaded exterior and an interior lip which compresses the peripheral ridge of elastomeric inflatable body against the projections of the molded cap structure when the sealant ring is joined to the molded cap structure. The molded cap having an inflation device that is suitable to regulate air flow through the upper surface of the cap and into the area contained within the inner most projection of the lower molded cap.

What is claimed is: 
     
       1. A pneumatic pipe plug comprising: (a) a molded cap structure having an upper and lower surface, the lower surface having two concentrically spaced projections which extend away from the lower surface, said projections including an inner most projection extending downwardly further than an outer most projection from said lower surface, said projections being further surrounded by a peripheral border, said cap having an inflation device suitable to allow air to pass through the upper surface of the cap and into the area contained within the inner most projection;   (b) an elastomeric, semi-rigid inflatable body having a closed bottom end, and an open top end having a peripheral shoulder extending therefrom, said peripheral shoulder further having a downwardly extending peripheral ridge, the opening of said top end being of sufficient diameter to receive said inner most projection of said molded cap, said outer most projection being of sufficient diameter to contact said peripheral shoulder of said molded cap; and   (c) a sealant ring having inside and outside surfaces, said inside surface having a lip which compresses said inflatable body's downwardly extending peripheral ridge, said outer surface having exteriorly disposed threads, said sealant ring being of sufficient diameter to contact said molded cap's lower surface peripheral boarder.   
     
     
       2. The pneumatic pipe plug of claim 1 wherein said molded cap has an externally threaded valve stem which passes through the molded cap structure and extends from the upper surface of said cap. 
     
     
       3. The pneumatic pipe plug of claim 1 wherein said upper surface of the molded cap structure has a graspable projection extending therefrom to allow rotation of the pipe plug by a human hand. 
     
     
       4. The pneumatic pipe plug of claim 1 wherein said sealant ring and said peripheral border of the molded cap structure are secured together by means of a solvent cement.